scholarly journals Protection of mice against Human respiratory syncytial virus by wild-type and aglycosyl mouse–human chimaeric IgG antibodies to subgroup-conserved epitopes on the G glycoprotein

2006 ◽  
Vol 87 (5) ◽  
pp. 1267-1273 ◽  
Author(s):  
C. Mekseepralard ◽  
G. L. Toms ◽  
E. G. Routledge
Keyword(s):  
Respiratory Syncytial Virus ◽  
Human Respiratory Syncytial Virus ◽  
Igg Antibodies ◽  
Wild Type ◽  
Rt Pcr ◽  
Human Infants ◽  
Ns0 Cells ◽  
Heavy Chain Constant Region ◽  
Syncytial Virus

Monoclonal antibodies (mAbs) to conserved epitopes on the G glycoprotein of human respiratory syncytial virus (HRSV) subgroup A fail to neutralize the virus in cell culture in the absence of complement, but are protective in rodent models of infection. They may have potential as prophylactic agents in human infants. In order to investigate the role of Fc-dependent pathways in protection by one such antibody, 1C2, the VH and VL genes were isolated by RT-PCR and assembled with human κ light-chain and human γ1 heavy-chain constant-region genes to form two mouse–human chimaeras, which were expressed in NS0 cells. One of the chimaeras carried a wild-type γ1 chain, whilst the other had an aglycosyl mutation in the CH2 domain rendering the antibody defective in complement activation and FcγR binding. Whilst both chimaeric antibodies exhibited similar avidity for HRSV in ELISA, only the fully glycosylated wild type was capable of neutralizing the virus in the presence of complement. In mice passively immunized with either murine or wild-type γ1 chimaeric antibody, no virus could be recovered from the lungs 4 days after intranasal inoculation of HRSV. In mice immunized with the aglycosyl γ1 chimaera, however, virus was present in the lungs following challenge, although virus titres were significantly reduced compared with controls (P<0·005). These results indicate that the protective effect of this antibody is mediated by both Fc-dependent and Fc-independent pathways.

scholarly journals Epitope mapping of human respiratory syncytial virus 22K transcription antitermination factor: role of N-terminal sequences in protein folding

2005 ◽  
Vol 86 (4) ◽  
pp. 1103-1107 ◽  
Author(s):  
Blanca García-Barreno ◽  
John Steel ◽  
Monica Payá ◽  
Luis Martínez-Sobrido ◽  
Teresa Delgado ◽  
...  
Keyword(s):  
Protein Folding ◽  
Respiratory Syncytial Virus ◽  
Western Blotting ◽  
Epitope Mapping ◽  
Human Respiratory Syncytial Virus ◽  
N Terminus ◽  
Transcription Antitermination ◽  
Syncytial Virus ◽  
Antibody Epitopes

The reactivity of a panel of 12 monoclonal antibodies raised against the human respiratory syncytial virus 22 kDa (22K) protein was tested by Western blotting with a set of 22K deletion mutants. The results obtained identified sequences in the C-terminal half of the 22K polypeptide required for integrity of most antibody epitopes, except for epitope 112, which was lost in mutants with short N-terminal deletions. This antibody, in contrast to the others, failed to immunoprecipitate the native 22K protein, indicating that the N terminus of this protein is buried in the native molecule and exposed only under the denaturing conditions of Western blotting. In addition, N-terminal deletions that abolished reactivity with monoclonal antibody 112 also inhibited phosphorylation of the 22K protein previously identified at Ser-58 and Ser-61, suggesting that the N terminus is important in regulating the 22K protein phosphorylation status, most likely as a result of its requirement for protein folding.

scholarly journals Human respiratory syncytial virus methyl transferase: a potential antiviral target?

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 750
Author(s):  
Raj Kalkeri ◽  
Govinda Bhisetti ◽  
Nagraj Mani
Keyword(s):  
Respiratory Syncytial Virus ◽  
Viral Replication ◽  
Sequence Similarity ◽  
Human Respiratory Syncytial Virus ◽  
Methyl Transferase ◽  
Mtase Activity ◽  
Literature Reviews ◽  
Host Innate Immune Response ◽  
Syncytial Virus

Human respiratory syncytial virus (HRSV) causes bronchiolitis and pneumonia. The role of methyltransferase (MTase) activity of HRSV polymerase in viral replication is unknown. Literature reviews of similar viral MTases and homology- modeling of RSV MTase bound to GTP and S-adenosylmethionine (SAM) have shown sequence similarity and the conserved catalytic residues (K-D-K-E) and the SAM-binding (GXGXG) domain. Combined with the recent reports of the importance of 2’O methylation of viral RNAs in the host innate immune response evasion, and its proposed role in viral replication, HRSV MTase holds promise as a potential antiviral target. Further biological validation of HRSV MTase could facilitate the discovery of novel HRSV antivirals targeting MTase enzyme activity.

scholarly journals Recombinant Respiratory Syncytial Virus (RSV) Bearing a Set of Mutations from Cold-Passaged RSV Is Attenuated in Chimpanzees

1998 ◽  
Vol 72 (5) ◽  
pp. 4467-4471 ◽  
Author(s):  
Stephen S. Whitehead ◽  
Katalin Juhasz ◽  
Cai-Yen Firestone ◽  
Peter L. Collins ◽  
Brian R. Murphy
Keyword(s):  
Respiratory Syncytial Virus ◽  
Recombinant Virus ◽  
Wild Type Strain ◽  
Nucleotide Sequence Analysis ◽  
Missense Mutations ◽  
Wild Type ◽  
Vaccine Candidates ◽  
Rsv Infection ◽  
Syncytial Virus

ABSTRACT A set of five missense mutations previously identified by nucleotide sequence analysis of subgroup A cold-passaged (cp) respiratory syncytial virus (RSV) has been introduced into a recombinant wild-type strain of RSV. This recombinant virus, designated rA2cp, appears to replicate less efficiently in the upper and lower respiratory tracts of seronegative chimpanzees than either biologically derived or recombinant wild-type RSV. Infection with rA2cp also resulted in significantly less rhinorrhea and cough than infection with wild-type RSV. These findings confirm the role of thecp mutations in attenuation of RSV and identify their usefulness for inclusion in future live attenuated recombinant RSV vaccine candidates.

scholarly journals Human respiratory syncytial virus methyl transferase: a potential antiviral target?

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 750
Author(s):  
Raj Kalkeri ◽  
Govinda Bhisetti ◽  
Nagraj Mani
Keyword(s):  
Respiratory Syncytial Virus ◽  
Viral Replication ◽  
Sequence Similarity ◽  
Human Respiratory Syncytial Virus ◽  
Methyl Transferase ◽  
Mtase Activity ◽  
Literature Reviews ◽  
Host Innate Immune Response ◽  
Syncytial Virus

Human respiratory syncytial virus (HRSV) causes bronchiolitis and pneumonia. The role of methyltransferase (MTase) activity of HRSV polymerase in viral replication is unknown. Literature reviews of similar viral MTases and homology- modeling of RSV MTase bound to GTP and S-adenosylmethionine (SAM) have shown sequence similarity and the conserved catalytic residues (K-D-K-E) and the SAM-binding (GXGXG) domain. Combined with the recent reports of the importance of 2’O methylation of viral RNAs in the host innate immune response evasion, and its proposed role in viral replication, HRSV MTase holds promise as a potential antiviral target. Further biological validation of HRSV MTase could facilitate the discovery of novel HRSV antivirals targeting MTase enzyme activity.

Use of rapid human respiratory syncytial virus strip tests for detection of bovine respiratory syncytial virus in experimentally vaccinated calves

2012 ◽  
Vol 15 (4) ◽  
pp. 629-634 ◽  
Author(s):  
W. Socha ◽  
J. Rola
Keyword(s):  
Respiratory Syncytial Virus ◽  
Rapid Test ◽  
Bovine Respiratory Syncytial Virus ◽  
Human Respiratory Syncytial Virus ◽  
Rt Pcr ◽  
Antigen Elisa ◽  
Nasal Swabs ◽  
Syncytial Virus ◽  
Type 3 ◽  
Reference Strains

AbstractThree different rapid strip tests: TRU RSV, BinaxNOW RSV and RSV Respi-strip were compared with RT-PCR and ELISA BRSV Ag for the ability to detect bovine respiratory syncytial virus (BRSV) in nasal swabs collected from calves experimentally vaccinated with live vaccine Rispoval RS-PI3. The reference strains of BRSV (375 and A51908) were detected by ELISA BRSV Ag whereas the strains of human respiratory syncytial virus (HRSV) and bovine parainfluenza virus type 3 (BPIV-3) were not. All rapid strip tests as well as RT-PCR reacted positively both to HRSV and BRSV reference strains and negatively to BPIV-3. The detection limit for RT-PCR was 39.1 TCID50 (strain 375 of BRSV), whereas for each of the rapid tests it was approximately 156 TCID50 and 312 TCID50 for antigen ELISA. Diagnostic sensitivity in detecting BRSV in nasal swabs for TRU RSV and RSV Respi-strip tests was 33% and 50% for BinaxNOW RSV. Diagnostic specificity of TRU RSV was 100%, whereas for both BinaxNOW and Respi-strip it was 87%. We concluded that TRU RSV could be used as a supportive rapid test for BRSV screening in nasal swabs taken directly on a farm. However, due to the small group of animals used in the experiment, the results should be regarded as preliminary and the study should be repeated on a larger number of animals.

scholarly journals A Respiratory Syncytial Virus Attachment Gene Variant Associated with More Severe Disease in Infants Decreases Fusion Protein Expression, Which May Facilitate Immune Evasion

2020 ◽  
Vol 95 (2) ◽  
pp. e01201-20
Author(s):  
Stacey Human ◽  
Anne L. Hotard ◽  
Christina A. Rostad ◽  
Sujin Lee ◽  
Louise McCormick ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Point Mutation ◽  
Stop Codon ◽  
Transcription Termination ◽  
Wild Type ◽  
Protein Levels ◽  
One Stop ◽  
Syncytial Virus ◽  
Tandem Stop Codons

ABSTRACTThis study identified a genotype of respiratory syncytial virus (RSV) associated with increased acute respiratory disease severity in a cohort of previously healthy term infants. The genotype (2stop+A4G) consists of two components. The A4G component is a prevalent point mutation in the 4th position of the gene end transcription termination signal of the G gene of currently circulating RSV strains. The 2stop component is two tandem stop codons at the G gene terminus, preceding the gene end transcription termination signal. To investigate the biological role of these RSV G gene mutations, recombinant RSV strains harboring either a wild-type A2 strain G gene (one stop codon preceding a wild-type gene end signal), an A4G gene end signal preceded by one stop codon, or the 2stop+A4G virulence-associated combination were generated and characterized. Infection with the recombinant A4G (rA4G) RSV mutant resulted in transcriptional readthrough and lower G and fusion (F) protein levels than for the wild type. Addition of a second stop codon preceding the A4G point mutation (2stop+A4G) restored G protein expression but retained lower F protein levels. These data suggest that RSV G and F glycoprotein expression is regulated by transcriptional and translational readthrough. Notably, while rA4G and r2stop+A4G RSV were attenuated in cells and in naive BALB/c mice compared to that for wild-type RSV, the r2stop+A4G RSV was better able to infect BALB/c mice in the presence of preexisting immunity than rA4G RSV. Together, these factors may contribute to the maintenance and virulence of the 2stop+A4G genotype in currently circulating RSV-A strains.IMPORTANCE Strain-specific differences in respiratory syncytial virus (RSV) isolates are associated with differential pathogenesis in mice. However, the role of RSV genotypes in human infection is incompletely understood. This work demonstrates that one such genotype, 2stop+A4G, present in the RSV attachment (G) gene terminus is associated with greater infant disease severity. The genotype consists of two tandem stop codons preceding an A-to-G point mutation in the 4th position of the G gene end transcription termination signal. Virologically, the 2stop+A4G RSV genotype results in reduced levels of the RSV fusion (F) glycoprotein. A recombinant 2stop+A4G RSV was better able to establish infection in the presence of existing RSV immunity than a virus harboring the common A4G mutation. These data suggest that regulation of G and F expression has implications for virulence and, potentially, immune evasion.

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